Frequently asked questions

Is it really free?

Yes — the simulator, the G-code export, USB and Wi-Fi streaming, the shape library: free, no signup required to use any of it. Accounts unlock saving projects, publishing shapes, and (later) tester-only firmware. There is no hidden tier.

How can I thank you or support you?

Talk about cncfoam.com on the internet, share the story, use the tool and be happy. Pete is not building for money, Pete is building for fun — sharing his knowledge, hoping to help someone like you to make your day more interesting.

What does my browser need?

Any modern browser (Chrome / Edge / Opera / Arc / Brave / Firefox / Safari) renders the simulator. Streaming over USB-Serial needs Chromium-based browsers (Chrome / Edge / Opera / Arc / Brave) — that's a WebSerial requirement, not ours. Firefox and Safari users fall back to the Download G-code button.

Do I need to install anything?

No. The tool runs entirely in the browser. The page is < 200 KB; first visit is a few seconds on a 4G connection.

Will it work offline?

Not yet — offline-first PWA is on the roadmap. Bookmark the page; for now you need a live connection on first load.

What machines does it work with?

Anything that eats standard 4-axis G-code (G01 X Y U V Z W F + M8 / M9). The reference target is ESP32 + FluidNC — flashed via the FluidNC web UI, configured with our YAML. The original 2015 Foamcube V4 stack (Arduino Mega + RAMPS 1.4 + custom firmware) also works — use the Download button and the machine's SD card. GRBL boards work for 2-axis modes.

Can it talk to a printer-style CNC like a 3D printer board?

If the board firmware understands plain G-code over serial (Marlin, RepRap, GRBL) it can be made to drive a hot-wire — but Marlin/RepRap doesn't natively understand 4-axis (X/Y + U/V). Stick to FluidNC for new builds.

Do I need a 4-axis machine?

No. Pick Settings → Machine settings → Kinematics → 2-axis and the tool mirrors the right-tower onto the left, hides U/V, and disables two-profile morph. Straight extruded shapes (signs, mouldings, lettering, single-section wings) only need 2 axes.

What about hot-wire safety?

Use a dedicated PSU on the wire, MOSFET driven from FluidNC's spindle PWM, INA226 current sense for closed-loop temperature. The hardware page has the BOM. Always have ventilation when cutting EPS / EPP / EVA — see the material info card in the tool for per-material risks.

What materials can it cut?

Hot wire cuts thermoplastic foams cleanly: EPS, XPS, EPP, PE, EVA. It also handles modelling wax. Pick the material in the left panel and the popup shows wire temp / speed / melting / burning / health risk for that one. Not wood, metal, MDF, or thermoset foams (polyurethane often chars instead of cutting).

How small / how big can I cut?

Bounded by your machine envelope. Default cutter is 500 × 500 × 500 mm; set yours in Settings → Cutter size. The tool warns when a part exceeds the envelope or the material block. Smallest practical detail = roughly twice the wire diameter (0.6 mm with the default 0.3 mm wire).

How long will my cut take?

Load a part, press ▶ Play, watch the timer above the scrub bar. That's at simulator speed — real machine time uses your Feedrate setting (mm/s) and depends on total cut perimeter. The shape library publishes the cut-time estimate on each shape page.

Why is my cut wavy / melty / fraying?

Most often: feedrate too slow for the wire temp (melts), or too fast (drags / waves). Open the material info card — match the suggested speed range to your foam. If your cut path has very different perimeters on the L vs R tower, the wire over-melts on the shorter side — the tool warns when this ratio exceeds 1.5×.

Why does my upload need moderation?

Stops spam, copyright-infringing dumps, and broken files. Admins approve in the queue; usually quick. If you're the admin yourself, your uploads bypass moderation.

Can I upload my proprietary shape?

You can — but anything published is public to everyone, including for download as source. There's no private library yet (on the roadmap). If your shape is sensitive, keep it as a "Saved project" in your account — those are private to you.

What file formats?

SVG, DXF, G-code (.gcode, .nc, .txt). .nc / .txt files are sniffed for actual G-code content and rejected if it doesn't look right.

Will my morph cut survive a publish-and-reload?

Yes. The tool's 📤 Publish button serialises the full 4-axis G-code with both X/Y and U/V tracks, the library auto-detects morphs (X≠U or Y≠V on any move) and renders the dual-profile preview + a lofted 3D solid on the detail page.

Do I need an account to use anything?

No. The tool, the gallery, downloads, USB and Wi-Fi streaming — all anonymous. Accounts unlock saving named projects, publishing shapes, liking + commenting.

What does signup ask for?

Email + password (8+ characters) + an optional display name. We send a verification link; click it and you're done. The verify link expires in 48 hours.

I lost my password.

Reset it here — we'll email a one-time link, valid for 60 minutes.

Will my settings follow me to another device?

Yes when you're signed in — every CFG change auto-syncs to your profile and the next device loads it. Signed-out, settings live in localStorage on that one browser.

Where does my data live?

On our server, in a single SQLite file. Your email + bcrypted password + the shapes / projects you save. We never sell, share, or train on your data. AI-training crawlers are blocked at robots.txt.

Can I delete my account?

Email [email protected] and we'll wipe your row + everything tied to it (projects, shapes, comments, likes). Self-service delete is on the to-do list.